Brane webs in the presence of an O5−O5^--plane and 4d class S theories of type D

In this article we conjecture a relationship between 5d SCFT's, that can be engineered by 5-brane webs in the presence of an $O5^-$-plane, and 4d class S theories of type D. The specific relation is that compactification on a circle of the former leads to the latter. We present evidence for this conjecture. One piece of evidence, which is also an interesting application of this, is that it suggests identifications between different class S theories. This can in turn be tested by comparing their central charges.Comment: 30 pages, 18 figures; v2 minor revision, version published in JHE

Grow rich and clean up later? International assistance and the provision of environmental quality in low- and middle-income countries

This paper deals with the question whether low- and middle-income countries that are politically better integrated into the international system are able to provide higher levels of environmental quality than could be expected only according to their national income levels. Using time-series cross-section regression analysis of 110 countries for the period 1950-1999 it can be shown that those countries that have signed and ratified more environmental treaties, have significantly lower SO2 emissions than countries that are less integrated into the international system. However, in contrast to theoretical predictions democratic low- and middle-income countries despite their stronger integration into the international system exhibit higher SO2 emissions indicating lower environmental quality than autocratic countries. --

Libraries in Switzerland

Ausgehend von einem historischen Überblick schildert der Beitrag die Entwicklung der Schweizer Bibliotheken in der Zeit von 1970 bis 2010: soziopolitischer Kontext, Struktur des Bibliothekswesen, technischer Wandel, wichtigste Akteure und aktuelle Herausforderungen. Starting with a brief history of libraries in Switzerland, this report focusses on the development of Swiss libraries from 1970 to 2010: socio-political context, structure of the Swiss library sector, change driven by technology, main actors, and challenges at the beginning of the new millennium. Suite à un aperçu historique, l'article décrit le développement des bibliothèques suisses dans la période de 1970 à 2010: le contexte socio-politique, la structure du secteur des bibliothèques, les changements technologiques, les principaux acteurs et les défis actuels

Comments on the twisted punctures of AevenA_\text{even} class S theory

We point out that the $\text{USp}$ symmetry associated to a full twisted puncture of a class S theory of type $A_\text{even}$ has the global anomaly associated to $\pi_4(\text{USp})=\mathbb{Z}_2$. We discuss manifestations of this fact in the context of the superconformal field theory $R_{2,2N}$ introduced by Chacaltana, Distler and Trimm. For example, we find that this theory can be thought of as a natural ultraviolet completion of an infrared-free $\text{SO}(2N+1)$ gauge theory with $2N$ flavors, whose $\text{USp}(4N)$ symmetry clearly has the global anomaly.Comment: 14 pages, 5 figures; v2: minor change